Physical activity and dietary behaviors developed early in life are likely to have long-lasting effects in reducing one's risk for obesity. Cross-promotional tie-ins, which link entertainment characters to advertised products, are often used to effectively market low- nutrient foods to young children. However, this strategy is underutilized for marketing healthy behaviors to children. Aims: The overarching goal of the proposed study is to develop and test a multi-component intervention for preschool and home-based use that uses a cross-promotional tie-in strategy to promote fruit and vegetable intake and physical activity to 3-5 year old children. Intervention: The intervention, titled Anytime Fitness, will link an Emmy award-winning educational television series, PEEP and the Big Wide World(R), with simple, behavior-based messages to incorporate healthy eating and structured physical activity into the daily lives of young children. The intervention will include: 10-14 9-minute PEEP episodes and related promotional materials; a 6-unit preschool and home-based curriculum; a website; and teacher and parent support. Methods: The multi-component intervention will be developed in partnership with WGBH, the PBS Boston affiliate and nationally recognized leader in children's educational entertainment media. Intervention development will be informed by formative research, including focus groups with preschool teachers and parents, and child testing panels. Once designed, the intervention will be implemented over a 12-week period in four diverse childcare settings, including private center-based daycares, a public preschool, and a HeadStart program. Parents of children attending these programs will be invited to simultaneously use the curriculum at home. Teacher and parent surveys and classroom observations will be used to assess feasibility of implementation and receptivity to the intervention. Physical activity will be assessed using Actigraph accelerometers. Parents will report on child dietary intake using a 3-day food record, and child media use with 7-day recall. Significance: Our intervention, Anytime Fitness, uses an established marketing tactic - linking persuasive messaging with children's favorite characters - to promote, rather than discourage, healthy habits. This fusion between entertainment media and rigorous public health research exemplifies the type of counterprogramming recommended by the American Academy of Pediatrics.